Correct Answer - Option 3 : leading
Concept:
- The overall power factor is defined as the cosine of the angle between the voltage and current.
- In AC circuits, the power factor is also defined as the ratio of the real power flowing to the load to the apparent power in the circuit. Hence power factor can be defined as watts to volt-amperes.
- It is also defined as the ratio of resistance to the impedance of the circuit.
Power factor \(= \cos ϕ = \frac{R}{Z}\)
ϕ is the phase difference between the voltage and current. If the current leads the voltage, then the power factor will be leading. If the current lags the voltage, the power factor will be lagging.
- In a purely capacitive circuit, the current leads the voltage by 90°
- In a series RC circuit, the current leads the voltage by an angle in between 0 to 90°
- In a purely inductive circuit, the current lags the voltage by 90°
- In a series RL circuit, the current lags the voltage by an angle in between 0 to 90°
- In a purely resistive circuit, both the current and voltage are in phase.
Calculation:
It is given that an impedance consists of resistance and capacitance. So, it is an RC circuit and hence the current leads the voltage by an angle in between 0 to 90°.
Therefore, the power factor is leading and it lies between 0 and 1.
Note:
- In a purely capacitive circuit, the power factor is zero leading.
- In a series RC circuit, the power factor is leading and lies between 0 and 1.
- In a purely inductive circuit, the power factor is zero lagging.
- In a series RL circuit, the power factor is lagging and lies between 0 and 1.
- In a purely resistive circuit,the power factor is unity.
